Unable to reduce text selection using Bluetooth keyboard and iPad

Hello, I am using iOS 9, an iPad Air and an Apple Wireless Keyboard. When I select some text (for instance in the Note app or in Textastic app) using the keyboard, i.e. using Shift+arrows, I am only able to extend the selection and not to make it smaller. As an example, if I select the word BCD inside ABCDE and I press shift+right arrow now the selection will be extended to BCDE. If I then press shift+left arrow in order to "reduce the selection" (like in OSX), instead of getting BCD selected, I get ABCDE selected. I tried a lot of keys combinations but I have not been able to reduce the selection using the keyboard. Is it possibile to reduce it using keyboard? If not I will send a feedback to Apple beacuse I find this a very bad lack of feature!